The function of the drive means for the window shade, which are arranged on one side at an end of the winding shaft, requires a nonrotatable pin mounting of this end of the winding shaft. In prior-art designs, a shaft journal of polygonal cross section is used for this purpose, which is provided on an inner bearing part of the drive means and can be nonrotatably hung into a slot (which is open on the top side) of a bracket, which can be fastened to a wall or the like. A simple bearing gudgeon is usually provided at the other end of the winding shaft in prior-art designs, and this bearing gudgeon is inserted into a hole or a slot with a round bottom of a bracket provided for this end of the winding shaft, which consequently has a different design, after the shaft journal has been hung into the slot (which is open at the top) of the bracket. The different wall brackets for the two ends of the winding shaft mounting do not permit any subsequent modification of the operating side without changing the wall bracket.
A design reversed for mounting the winding shaft on the drive side with a support pin at the bracket on the wall and with a receiving slot for this support pin in an inner bearing part of the drive means of the winding shaft has been known from U.S. Pat. No. 4,372,432.